• Registered: 2019-05-21
  • Posts: 16

Topic: Concrete and steel bar strain

Hi

I'm working on RC continuos beam and simulated that on ATENA Engineering 3D. I used the N-R method with displacement-load control for loading my beam and made the monitor points for load (as Reactions) and deflection (as Displacement) as a value at node, and the result is good. But, my question is:

- how to get the correct strain values at a specific point in concrete and steel to make Load-strain relationl, athough i made monitor points for them as a value in integration point. I'm looking forward u reply ASAP, please

Thanks in advance

Quote Post 1

  • dpryl
  • CC software developer
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  • Registered: 2007-07-13
  • Posts: 1,107

Re: Concrete and steel bar strain

Dear ahmed, simply said, to get strain values comparable with some measured strains you should basically measure them the same way in your model. Depending on the strain gauge length, a single IP value may be the best approximation, or you need to calculate from 2 displacement monitors and their positions.

When defining a Monitoring Point, please do not forget to select the element type (Topological Data: Macroelements / Reinforcement bars / External cables).

Regards.

dpryl's Website

Quote Post 2

  • Registered: 2019-05-21
  • Posts: 16

Re: Concrete and steel bar strain

Hi,

Firstly, thanks for u reply but I have the following questions;

#How I consider the gauge length when
1- selecting IP, by taking two point with the distance between equal to the length of gauge and then take the average values between them and divided by the distance and that the strain

2- or selecting one IP is approx. enough to give me directly the strain

3- or repeat steps for number 1 but with two displacement monitors instead IPs.

# the second question, which strain type is suitable for concrete and strain (Engineering strain, Eq xx) or another type.

Thanks

Quote Post 3

  • dpryl
  • CC software developer
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  • Registered: 2007-07-13
  • Posts: 1,107

Re: Concrete and steel bar strain

Dear ahmed,
ad 1.: if the real measurement length corresponds to about the size covered by 2 (or 3) IPs, this may be a good solution.

Ad 2.: With linear elements, this is good if the gauge length is comparable to about 1/2 of the element size.

Ad 3.: I do not like the word "repeat" in this context as you are not going to average the displacements.

Ad 2nd question: typically, "Strain" would be the first choice. For more information, please see the ATENA 3D User's Manual, 5.5 Output Data Attributes.

Regards.

dpryl's Website

Quote Post 4